1. Field of the Invention
The present invention relates to a method for dyeing an optical component such as an eyeglass lens or optical filter.
2. Description of the Prior Art
As for example, there has been a great demand for colored eyeglass lenses as articles which are associated with the current fashion and style and are high in added value. In accordance with conventional lens coloring techniques, it has been the practice to repeat a plurality of times the operation of preparing a dyeing solution by dispersing a dye in a mainly water-type dispersion medium, maintaining the resulting dyeing solution at a temperature of 100.degree. C. or less under the atmospheric pressure, dipping a lens in the dyeing solution in this condition and taking out the lens from the solution thereby effecting the dyeing with the desired color tone and color density. In this case, generally it has been frequent to perform a so-called half coloring in which about one half of the area extent of a lens surface is dyed with a gentle color density gradient so as to gradually decrease the color tone toward the center of the lens.
However, the dyeing of optical components by the conventional method of the above-mentioned type is disadvantageous in that to obtain the desired color tone and color density tends to have recourse to the long experience of a dyeing operator, and particularly where the dyeing with a gentle color density gradient is effected, the reproducibility of products of the same finish is deteriorated and it is difficult to prevent variations in the color density due to the following processing operations such as a protective coating.